Question: Find the slope and y-intercept of the line that is ${\text{parallel}}$ to $\enspace {y = \dfrac{3}{2}x + 1}\enspace$ and passes through the point ${(7, 8)}$. ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$
Answer: Parallel lines have the same slope. The slope of the blue line is ${\dfrac{3}{2}}$ , so the equation of our parallel line will be of the form $\enspace {y = \dfrac{3}{2}x + b}\enspace$ We can plug our point, $(7, 8)$ , into this equation to solve for ${b}$ , the y-intercept. $8 = {\dfrac{3}{2}}(7) + {b}$ $8 = \dfrac{21}{2} + {b}$ $8 - \dfrac{21}{2} = {b} = -\dfrac{5}{2}$ The equation of the parallel line is $\enspace {y = \dfrac{3}{2}x - \dfrac{5}{2}}\enspace$. ${m = \dfrac{3}{2}, \enspace b = -\dfrac{5}{2}}$